#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int arr[100] = { 0 };
	int n = 0;
	scanf("%d", &n);
	for (int i = 0; i < n; i++)
	{
		scanf("%d", &arr[i]);
	}
	int left = 0;
	int right = n - 1;
	int k = 0;
	scanf("%d", &k);
	while (left <= right)
	{
		int mid = (left + right) / 2;
		if (arr[mid] < k)
		{
			left = mid + 1;
		}
		else if (arr[mid] > k)
		{
			right = mid - 1;
		}
		if(arr[mid]==k)
		{
			printf("%d", ++mid);
			break;
		}
	}
	if (left > right)
		printf("查无此数");
	return 0;
}